Chlorinated bis(silyl)benzenes



United States Patent 3,200,137 CHLORINATED filSiSiLYUBENZENES George M.Omietanski, Tonawanda, and Wallace G. Reid,

Grand Isiand, N.Y., assignors to Union Carbide Corporation, acorporation of New York No Drawing. Filed Sept. 29, 1961, Ser. No.141,623 3 Claims. (Cl. 260-4482) This invention relates to novelorganosilicon compounds. More particularly, this invention relates tonovel chlorinated organosilanes having the formula wherein X is a memberof the class consisting of halogen, hydroxy, alkoxy and acyloxy groups,n is an integer of from 0 to 2 and m is an integer of from 0 to 2.

Illustrative of the groups represented by X are the halogens, such as,fluorine, chlorine, bromine and the like; alkoxy groups such as,methoxy, ethoxy, propoxy, butoxy, octyloxy, octadecyloxy and the like;the acyloxy groups such as acetoxy, butyroxy, and the like; and hydroxygroups.

Illustrative of the novel chlorinated organosilan-es of this inventionare bis(trichlorosilyl)dichlo-robenzene, bismethyldifiuorosilyl)dichlorobenzene, bis (dimethylfluorosilyl)dichlorobenzene,bis(triethoxysilyl)dichlorobenzene,bis(methyldipropoxysilyl)dichlorobenzene, b'is(dimethylbutoxysilyl)dichlorobenzene, bi-s (hydroxydimethylsilyl dichlorobenzene,bis(acetoxydimethylsilyl)dichlorobenzene, and the like.

The novel chlorinated organosilanes of this invention wherein X ishalogen, are prepared by the react-ion of a b:is(silyl)benzene of theformula wherein Y is halogen as defined for X and m and n are asabove-defined, with chlorine gas employing anhydrous aluminum chlorideas a catalyst and carbon tetrachloride as a cataylst and carbontetrachloride as a solvent. The reaction which takes place isillustrated by the following equation showing the reaction of chlorinewith bis(dimethylchlo-rosily benzene bHa \ojlzc/ CH3 2 The reaction iscarried out according to the following general proocedure:

The bis-silyl benzene is dissolved in anhydrous carbon tetrachloride andaluminum chloride is added so that the solution contains from 0.01 toabout 2 percent by weight aluminum chloride. The solution is then heatedto from about 50 C. to its reflux temperature and chlorine gas isintroduced into the solution, preferably at a point near the bottom ofthe reaction vessel. The reaction mixture can be agitated only by thestream of chlorine gas or a mechanical means can be employed, ifdesired. After an amount of chlorine gas equal to about or in excess of2 3,200,137 Patented Aug. 10, 1965 moles of chlorine per mole of thebis-silyl benzene has been bubbled into the reaction mixture, themixture is cooled and filtered. "The filtrate is then distilled atatmospheric pressure or under reduced pressure to remove the carbontetrachloride. The residue is then fractionated at reduced pressure toyield the bis(silyl)dichlorobenzene.

The amount of anhydrous aluminum chloride employed as the catalyst forthis reaction can be from 0.01 to 2.0 parts by weight of aluminumchloride per parts by weight of the reaction solutions, that is, thebis-silylbenzene and carbon tetrachloride. It is preferred to employfrom 0.1 to 1.0 part by weight aluminum chloride per 100 parts by weightof the reaction solution for con- Venience and to obtain a reasonablerate of reaction.

It is preferred that the carbon tetrachloride employed as the solventfor the reaction be anhydrous so as to prevent side reactions such ashydrolysis of any hydrolyzable groups bonded to the silicon atom or thehydration of the aluminum chloride catalyst.

The bis-silyl-benzenes which can be employed as starting materials inproducing the novel chlorinated organosilanes of the invention are thosehaving the formula H H (0113),. 0:0 Y3-..si-0 /CSi-Ya-m H H where Y, nand m have the above-defined meanings.

The bis-silyl-benzenes are produced by a Grignard reaction employingpara-dibromobenzene and a chlorosilane of the formula, (CH SiCl whereinf is an integer of from 0 to 2.

The alkoxy and acyloxy bis-silyl-dichlorobenzenes of this invention isproduced by the reaction of the correspondingbis(halosilyl)dichlorobenzene with an alkanol or aliphatic acid wherebythe hydrogen of the OH group of the alkanol or .acid reacts with thehalo group of the bis- (halos-ilyl)dichlorobenzene to form thecorresponding hydrohalic acid and the bis(alkoxysilyl)dichlorobenzene orbis (acyloxysilyl) dichlorobenzene.

The bis(hydroxysilyl)dichlorobenzenes of this invention are produced bythe hydrolysis of the bis-(halo-, ;acyl-oxy-, oralkoxys-ilyl)dichlorobenzene in a benzene solution with an excess ofammonium hydroxides at 0 C.

The novel chlorinated organosilanes of this invention find utility asadditives to known silicone oils to improve their lubricity and/ orflame resistance. The novel chloronated organosilanes of the inventioncan also be cchydrolyzed and co-condensed by known procedures withsilanes of the formula, R SiX wherein X is as above defined, R is amonovalent hydrocarbon group such as methyl, ethyl, phenyl, naphthyl,vinyl, allyl, phenylethyl, tolyl and the like, and x is an integer offrom 0 to 3, under acidic or basic reaction to yield organopo'lysiloxanecopolymeric resins having improved fiame resistance or copolymerioorganopolysiloxane oils having improved flame resistance and improvedlubricity.

The following examples serve to further illustrate the invention.

Example 1 A 2-liter, S-necked flask was fitted with a stirrer, refluxcondenser and a gas inlet tube. A mixture of grams (0.4 mole) of1,4-bis(dimethylchlorosilyl)benzene, 300 grams of carbon tetrachloride,and 1.6 grams of anhydrous aluminum chloride Were placed in the flaskand the flask and contents heated to 70 C. A rapid stream of chlorinegas was passed through the mixture for 1 2 hours. The reaction mixturewas cooled, filtered and the filtrate distilled under reduced pressureto yield 43.0 grams (0.077 mole) of a product having a boiling point 3of 104110' C. at 3 mm. Hg, which was identified as1,4-bis(dimethylchlorosilyl)dichlorobenzene. The 1,4-bis-(dimethylchlorosilyl)dichlorobenzene gave the following analysis:

Calculated for C H Cl Si 22.7% C1; 6.8% Si. CI; 15.6% Si.

36.2% C; 3.9% H; Found 35.9% C; 4.3% H; 43.3%

Example 2 The product obtained in Example 1 was dissolved in 250 m1. ofbenzene and hydrolyzed with an excess of aqueous ammonium hydroxide atC. A gummy precipitate formed as the reaction warmed to roomtemperature. The gummy precipitate was recrystallized from hot benzeneand there was obtained 5.7 grams (15 mole-percent) of1,4-bis(dimethylhydroxysilyl)-2,5-dichlorobenzene, melting point withdecomposition 172176 C. The structure was verified by infra-redanalysis. Elemental analysis of the 1,4-'bis(dimethylhydroxysilyl)-2,

dichlordbenzene gave the following results:

Calculated for C H C1 O Si 40.6% C; 5.4% H; 24.0% CI; 19.0% Si. Found:40.6% C; 5.5% H; 21.9% C1; 18.8% Si.

Example 3 1,4-bis(dimethylhydroxysilyl)-2,5-dichlorobenzene was mixedwith about twice its weight of octamethylcyclotetnasiloxane andequilibrated and condensed at 150 C. for 16 hours employing cesiumhydroxide as a catalyst. There was obtained a tough polys-iloxane gumwhich had the odor of pdichlorobenzene.

The polysiloxane gum can be milled with a finely divided silica fillerand dibenzoyl peroxide according to standard procedures and then heatedto 250 F. for 15 minutes in a pre-heated mold (6" x 6" x .075") to yieldan elastomer.

What is claimed is: 1. An organosilicon compound having the formula(out). Xa-nSi-C References Cited by the Examiner UNITED STATES PATENTS2,499,561 3/50 Barry 260448.2

2,561,429 7/51 Sveda 260448.2

3,053,872 9/62 Omietanski 260448.2

3,117,149 1/ 64 Holdstock' 260-4482 FOREIGN PATENTS 1,246,989 "10/ 60France.

771,587 4/57 Great Britain.

' TOBIAS E. LEVOW, Primary Examiner.

ALPHONSO DfSULLIVAN, SAMUEL H. BLECH,

Examiners.

1. AN ORGANOSILICON COMPOUND HAVING THE FORMULA